South-East Asian theatre of World War II

Japanese forces met stiff resistance from III Corps of the Indian Army, the Australian 8th Division, and British units during the Battle of Malaya, but Japan's superiority in air power, tanks and infantry tactics drove the Allied units back. After being driven out of Malaya by the end of January 1942, Allied forces in Singapore, under the command of Lieutenant General Arthur Percival, surrendered to the Japanese on 15 February 1942; about 130,000 Allied troops became prisoners of war. The fall of Singapore was the largest surrender in British military history.

The Japanese Indian Ocean raid was a naval sortie by the Fast Carrier Strike Force of the Imperial Japanese Navy from 31 March to 10 April 1942 against Allied shipping and bases in the Indian Ocean. Following the destruction of the ABDACOM forces in the battles around Java in February and March, the Japanese sortied into the Indian Ocean to destroy British seapower there and support the invasion of Burma. The raid was only partially successful. It did not succeed in destroying Allied naval power in the Indian Ocean but it did force the British fleet to relocate from British Ceylon to Kilindini at Mombasa in Kenya, as their more forward fleet anchorages could not be adequately protected from Japanese attack. The fleet in the Indian Ocean was then gradually reduced to little more than a convoy escort force as other commitments called for the more powerful ships. From May 1942, it was also used in the invasion of Madagascar — an operation aimed at thwarting any attempt by Japan to use bases on the Vichy French controlled territory.

In 1942, Madras City was attacked by a Mitsubishi Rufe, (the Zero's seaplane version) operating from the carrier Ryūjō which dropped a single bomb near the St. George Fort.[7][8] The physical damage was negligible,[9] though the public response was major and the city was evacuated because of fears of subsequent Japanese bombing and invasion. Many rich families from Madras moved permanently to the hill stations in fear.[10]

Also in 1942[11] in preparation for a possible Japanese invasion of India, the British began improvements to the Kodaikanal-Munnar Road to facilitate its use as an evacuation route from Kodaikanal along the southern crest of the Palani Hills to Top Station. Existing roads then continued to Munnar and down to Cochin where British ships would be available for evacuation out of India.[12][13]

The Andaman and Nicobar Islands (8,293 km² on 139 islands) are a group of islands situated in the Bay of Bengal at about 780 miles from Kolkata (known at the time as Calcutta), 740 miles from Chennai (known at the time as Madras) and 120 miles from Cape Nargis in Burma. On 23 March 1942 a Japanese invasion force seized the islands and occupied them until the end of the war.

On 29 December 1943, political control of the islands was theoretically passed to the Azad Hind government of Subhas Chandra Bose. Bose visited Port Blair to raise the tricolour flag of the Indian National Army. After Bose's departure the Japanese remained in effective control of the Andamans, and the sovereignty of the Arzi Hukumat-e Hind was largely fictional.[14] The islands themselves were renamed "Shaheed" and "Swaraj", meaning "martyr" and "self-rule" respectively. Bose placed the islands under the governorship of Lt Col. A. D. Loganathan, and had limited involvement with the administration of the territory.

• Northern Combat Area Command (NCAC)
• Flying Tigers
• Fourteenth Air Force
• Tenth Air Force
• Twentieth Air Force (Operation Matterhorn)
• The Allied logistical airlift from India into China over the Hump
• The Ledo Road
• Merrill's Marauders

One of the major logistical efforts of the war was "flying the Hump" over the Himalayas and the building of the Ledo Road from India to China as a replacement for the Burma Road.

At the start of the war the British had two commands with responsibilities for possessions in the theatre. India Command under General Sir Archibald Wavell the Commander-in-Chief (CinC) of the Army of India and the Far East Command, first under Air Chief Marshal Robert Brooke-Popham and then from 23 December 1941 commanded by Lieutenant-General Sir Henry Royds Pownall.

India Command was responsible for British India, British Ceylon, and for some of the time Burma. The Far East Command based in Singapore was responsible for Hong Kong, Malaya, Singapore and other British Far East possessions including, for some of the time, Burma.

A month after the outbreak of war with Japan on 7 December 1941, the Allied governments jointly appointed the British Commander-in-Chief (CinC) of the Army of India, General Sir Archibald Wavell, as Supreme Allied Commander of all "American-British-Dutch-Australian" (ABDA) forces in South East Asia and the Pacific, from Burma to the Dutch East Indies.

However, advances made by the Japanese over the next month split the ABDA forces in two. After transferring the forces in Burma to the India Command, on 25 February 1942 Wavell resigned as commander of the ABDA and resumed his position of CinC of the Army of India. Responsibility for the South West Pacific Area passed to US General Douglas MacArthur as Supreme Allied Commander South West Pacific.

From February 1942 until November 1943 the India Command was responsible for the South East Asian Theatre. General Wavell was made Viceroy of India and General Claude Auchinleck became Commander-in-Chief of the India Command on 20 June 1943. In August 1943 the Allies formed a new South East Asian Command to take over strategic responsibilities for the theatre.

The reorganisation of the theatre command took about two months. On 4 October Winston Churchill appointed Admiral Lord Louis Mountbatten supreme Allied commander of the South East Asia Command (SEAC). The American General Joseph Stilwell was the first deputy supreme Allied commander. On 15 November, Auchinleck handed over responsibility for the conduct of operations against the Japanese in the theatre to Mountbatten.

The initial land forces operational area for SEAC included India, Burma, British Ceylon and Malaya. Operations were also mounted in Japanese-occupied Sumatra, Thailand and French Indochina (Vietnam, Cambodia, and Laos).

Initially SEAC commanded:

• British Eastern Fleet (based in Ceylon)
• British 11th Army Group (Commonwealth land forces; HQ in New Delhi)
• Air HQ India (New Delhi)
• China Burma India Theater (CBI), (all US forces in theatre; HQ in New Delhi).

In October 1944, CBI was split into US Forces China Theater (USFCT) and India-Burma Theater (USFIBT).

On 12 November 1944 Eleventh Army Group redesignated by Allied Land Forces South East Asia (ALFSEA) combining Commonwealth and US forces, with an HQ at Kandy. On 1 December ALFSEA HQ moved to Barrackpore, India.

On 15 August 1945 responsibility for the rest of the Dutch East Indies was transferred from the South West Pacific Area to SEAC.

SEAC was disbanded on 30 November 1946.

British 11th Army Group ( November 1943 – 12 November 1944) was on paper the main Commonwealth army force in South East Asia which directed

• British Fourteenth Army
• British Army in Ceylon (Ceylon Army)
• Northern Combat Area Command under the command of Joseph Stilwell.

On 12 November 1944 the 11th Army Group was redesignated Allied Land Forces South East Asia, still under SEAC, because it was felt that an inter-Allied command was better than the purely British headquarters. Command problems with General Stilwell and his interactions with the U.S. Joint Chiefs of Staff had precipitated the change.

The Imperial Japanese Army Unit controlling all army land and air units in South East Asia and the South West Pacific was the Southern Expeditionary Army headquartered in Saigon, Indochina. It was commanded by General Count Hisaichi Terauchi, who commanded it from 1941 to 1945. The Japanese also deployed the South Seas Force, a combined force of Army and Special Naval Landing Force personnel. The Southern Army's major field commands were the 14th Army, the 15th Army, the 16th Army and the 25th Army. These consisted of 11 infantry divisions, six independent infantry brigades, and six tank regiments, plus artillery and support troops. The Japanese extensively used bicycle infantry, which allowed them quick movement over vast distances.